小编rod*_*757的帖子

如何在 spring data jpa 中执行本机查询，同时获取子实体？如果我在子实体对象上有 Eager FetchType，则 spring 数据正在执行 2 个查询。1 为父实体，1 为子实体。

有没有办法只执行 1 个本地查询来获取父实体和子实体？

家长：

@Entity
public class Parent {
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private long id;

   @Temporal(TemporalType.TIMESTAMP)
   private Date ts;

   @ManyToOne(fetch=FetchType.LAZY)
   private Child child;
}

孩子：

@Entity
public class Child {
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private long id;

   @OneToMany(fetch=FetchType.LAZY, mappedBy="parent")
   private Parent parent;
}

询问：

public interface ParentRepository extends Repository<Parent, Integer> {
    @Query(value = "SELECT * from parents p inner join children c on c.id=p.childId where TIMESTAMPDIFF(SECOND, …

有没有办法使用Spring的LocalContainerEntityManagerFactoryBean和Hibernate在包中排除实体？如果重要的话,我正在使用spring-data.我想用另一个数据源管理被排除的实体.我知道你可以使用hibernateSessionFactory(在扫描PackagesToScan时忽略一些类)来做到这一点,但我更愿意使用jpa.

这是我的配置:

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:jpa="http://www.springframework.org/schema/data/jpa"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
       http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd ">

    <context:property-placeholder location="classpath:app.properties" ignore-unresolvable="true"/>

    <bean id="dataSource"
          class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${class}" />
        <property name="url" value="${url}" />
        <property name="username" value="${user}" />
        <property name="password" value="${password}" />
    </bean>

    <bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
    </bean>

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
        <property name="packagesToScan">
                <value>com.mypackage.new.entities</value>
        </property>
        <property name="jpaProperties">
            <props>
                <prop key="hibernate.hbm2ddl.auto">validate</prop>
                <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
                <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
                <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
                <prop key="hibernate.id.new_generator_mappings">true</prop>
                <prop key="hibernate.max_fetch_depth">3</prop>
            </props>
        </property>
    </bean>

    <!-- Enables …

如何获取没有字段中任何对象的所有文档？

我有以下映射:

"properties" : {
  "name": {
    "type": "text"
  },
  "nestedArray": {
    "type": "nested",
    "properties": {
      "prop1": {
        "type": "text"
      },
      "prop2": {
        "type": "text"
      }
    }
  }
}

我希望得到"nestedArray"为空或不存在的所有文档.

我正在使用elasticSearch 5.0